1. Field of the Invention
The present invention relates to an image data output apparatus for outputting image data.
2. Related Background Art
In recent years, image data scanning apparatuses connected to various data processors and printers for printing out image data have advanced performance, and have very high scanning and print-out resolutions (e.g., 300 dots/inch or higher).
However, in a data processor to which these apparatuses are connected, the high resolution data cannot be processed without modifications due to limitations such as a memory capacity, a processing speed, and the like. A display apparatus connected to the data processor is also of a low resolution type. For this reason, data quantity is decrease through data compression processing and the like and is converted to low-resolution data to perform processing.
Even if an image data scanning apparatus sends high-resolution image data to the data processor, low-resolution print data is output from the data processor to a printer. Thus, the performance of the printer cannot be sufficiently utilized.
When high-resolution image data is communicated between the data processor and the printer without modifications, this requires a long transfer time, and the performance of the printer cannot be sufficiently utilized.
In recent years, image data scanning apparatuses connected to various data processors and printers for printing out image data have advanced performance, and a compact, low-price type apparatus is also available. These apparatuses can be connected to office computers and wordprocessors.
Low-price apparatuses such as printers connected to the data processor are needed, and the type of machine to be connected is not determined. Thus, these apparatuses preferably have compatibility.
Interfaces of printers serving as image data output apparatuses have standards. For example, the "RS-232C" as a serial interface and the "Centronics" interface as a parallel interface are widely used. However, image data scanning apparatuses are new in the market and have no interface standards. For this reason, only one type of image data scanning apparatus can be connected to the data processor, and a control sequence (control program) having a specific protocol must be created.
In a conventional image data scanning apparatus, the scanned data is received by a host side without modifications. Therefore, a large volume of data must be communicated. However, the host side does not require high resolution data in the case of CRT display or page layout, resulting in inconvenience.